


It's Never Simple

by Risitka



Series: Summer Changes [2]
Category: Invader Zim
Genre: Angst, Dib panics, Gaz tries to be support, Irkens are different, M/M, Mpreg, Smut, ZaDr, Zim keeps secrets
Language: English
Status: Completed
Published: 2020-07-29
Updated: 2020-08-04
Packaged: 2021-03-05 21:42:12
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 2,814
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25582297
Author URL: https://archiveofourown.org/users/Risitka/pseuds/Risitka
Summary: Dib gets an answer to his question and Zim tries to calm him down.However, Zim didn't mention something important about how this works.
Relationships: Dib & Gaz (Invader Zim), Dib/Zim (Invader Zim), Gaz & Zim (Invader Zim)
Series: Summer Changes [2]
Series URL: https://archiveofourown.org/series/1854085
Comments: 6
Kudos: 83





	1. Surprise!

**Author's Note:**

> I have a good ending and a bad ending in mind for this.  
> Even I'm not sure which one my brain will let me write.

Nothing had really changed since they officially started dating two months ago. Movie nights still happened at Zim's base every week, albeit with the bonus of cuddles and kisses now. And occasionally Zim would show up in Dib's room at night to lay beside him. Dib loved those nights. He loved being able to just hold Zim close in silence or, if he was lucky, talk about space and all the things Zim had seen.

Tonight was neither and Dib was alone. It was past the time that Zim would come over so Dib stretched out and stared at the glow in the dark stars above his head. His mind wandered back to Zim’s heat and he blushed as heat rushed through him. He reached under the blanket to palm himself, but kept thinking. He definitely wanted to have sex with Zim again. Preferably outside of a heat, but he didn’t know if Zim wanted to. For all he knew it could be a heat-only thing. And then there was the chance of pregnancy. Zim had told him that it would take a while to know if he already was, and that he would let Dib know. So at least he didn’t have to worry about that. Maybe he should buy some condoms just in case. With a groan he pushed his pants down as he thought more about it, closing his eyes as he fantasized. He was getting so close…

“Dib?” A quiet voice startled him back to the present. Dib shrieked, pulling his hand away from himself and pulling the covers up further.

“Z-Zim?!” Dib flushed as Zim hesitantly sat on the edge of the bed with wide eyes.

“Sorry… I didn’t mean to scare you. Are you okay?” Zim’s antennae twitched. “You smell like… What were you doing Dib?”

“Um… I… I wasn’t… It’s past the time you normally show up.” He mumbled out, looking away.

“Oh… Should I leave? You seemed… busy.” Dib groaned and sat up, cradling his head in his hands.

“You’re fine. I was just…” He groaned again as his blush deepened. Zim suddenly stood up.

“ _Oh._ Zim will see you tomorrow instead. You can… get back to your…” He trailed off and Dib looked up in time to see Zim’s blush before he leapt back out the window.

“…Oh _fuck_.” He curled into bed, shoving his head into his pillows.

* * *

Dib trudged to Zim’s house the next day. He hadn’t been able to get to sleep after that much embarrassment and he was hoping Zim wouldn’t bring it up. Opening the door he looked around to see Zim sitting on the couch, a small smile forming as Dib went to sit next to him. Zim leaned over to kiss his cheek before settling back and turning on a movie.

By the time the credits rolled Dib had an arm wrapped around Zim and was smiling. It was a cute movie and the family was reunited at the end. He loved family movies like that. He turned to Zim to see him with a small frown.

“Zim? Something wrong?”

“Eh? Oh… I was just thinking…”

“Oh? What about?”

“… Do you want kids Dib?”

“What!?” Dib pulled away to look at Zim fully. “Why are you asking that?!”

“You seemed to like watching the family in the movie.” Zim gave him a confused look. “And Gir was screaming something about liking babies yesterday.” He frowned and Dib slumped back in relief.

“Oh, ok.”

“So?”

“Well… I dunno Zim. I mean I guess I’d like to have a kid someday. But definitely not right now or anything.” He sighed and stared at the ceiling. “Yeah, someday after college and everything, I’d like to be a dad.” He smiled sheepishly and turned back to Zim. “What about you Zim? Do you want kids?”

“… I… I don’t know.” Zim didn’t look at Dib as he stood. “It’s getting late so you should probably-“

“DID I MISS DA MOVIE?!”

“You did Gir. Stop shouting.”

“NOOOO!!! I WANNA WATCH THE MOVIE!” Gir began to scream and Dib picked him up while Zim scowled.

“I’m not that tired. We can re-watch it.” Gir grinned up at Dib and bounced onto the floor. Zim sighed and turned to leave.

“I have other things to do. You two have fun.” He left before Dib could say anything.

* * *

Halfway through the movie Dib was just laying on the couch and not really paying attention when Gir poked his cheek. Dib pushed his hand away and groaned.

“Are you and Mastah gonna keep the baby?” He loudly whispered.

“What? What baby?”

“YOUR baby!” Gir giggled and Dib sat up to stare at the robot.

“Gir. What are you talking about?”

“I like babies!”

“GIR!”

“Mastah said uh… He said he has a baby if you want it!” Gir grinned and flopped back onto the floor to continue watching the movie. Dib stared at him for a moment before jumping up and running over to the elevator. Once downstairs he ran over to Zim in a panic. Zim just cocked his head to the side.

“Dib? What’s wrong? Did Gir make a mess again?”

“Are you pregnant?!” Dib shouted, grabbing Zim’s shoulders. Zim’s antennae flattened against his head instantly and Dib stumbled back. “Fuck… You are?! Why didn’t you tell me?! I can’t have a kid right now Zim! We start college in like a month.” He began to ramble in his panic, stopping when Zim grabbed his arm.

“Calm down. You do not want it so Zim will not be having it.”

“Oh… You can abort it? Good… That’s good… Sorry for freaking out…” Dib smiled weakly and kissed Zim quickly before heading back upstairs. Zim watched him go before sighing and sitting down.

“Computer… How long until the miscarry?”

**“18.3 hours left.”**

“… I wish Dib wanted it…”


	2. Time is of the Essence

The next day Gaz slammed open Dib’s door, laughing when he fell out of bed.

“What the fuck Gaz!?”

“Oh calm down. It’s past ten all ready, not my fault you don’t wake up at a decent time.”

“It’s summer Gaz, I shouldn’t have to!”

“Whatever.” She leaned against the doorframe. “So did something happen last night? You looked totally freaked when you came home last night. Didn’t even notice me and Dad greeting you.”

“Dad’s home?”

“Well yeah. Every week, remember?”

“Right… Sorry I missed dinner.” He got back on his bed and ran a hand through his hair. “Last night was weird.”

“He said we can have lunch together today instead. So what was weird? Fighting with Zim?”

“No. Actually it’s fine. It’s all figured out.”

“What is shit head?”

“Zim’s pregnant.” He held up his hands when Gaz’s eyes widened. “It’s ok! He’s not keeping it.” Dib smiled nervously. “He had asked if I wanted kids and I told him no. We’re a bit young you know? So he said he’s not keeping it.” Dib was shoved back onto the floor.

“So he’s getting rid of it because _you_ don’t want it?! Did you even ask if he wants it?!”

“What?”

“Does he want to keep it?”

“Of course not! Why would he…” Dib frowned as Gaz slammed his door shut as she left.

Gaz let herself into Zim’s base, kicking Gir out of the way when he tried to grab her legs. She glanced around angrily before heading down. She paused once in the lab and looked around.

“Zim!” She shouted as she walked around, eventually turning and heading down the hallway when a door opened.

“Gaz? What are-“ Gaz pushed her way into the room and sat on the bed, glaring at the floor.

“Dib said you’re pregnant.”

“Oh…” He hesitantly sat down. “Yes, but it doesn’t matter. Zim will not be keeping it.”

“Because Dib doesn’t want a kid?”

“Yes.”

“What about you Zim? Do you want to keep it?”

“It… doesn’t matter.”

“Of course it fucking matters!” She stood back up to glare at him. “It’s not just Dib’s decision! If you want the kid then you should keep it! Don’t let Dib make the choice for you!” Zim was quiet for a while, not looking up at her even when she sat back down.

“It’s not that simple Gaz…” He spoke quietly and Gaz leaned closer to hear him. “Irkens…” He sighed. “It’s not the same as humans. We can’t keep the smeet if our partner does not want it.”

“What? Zim…”

“I don’t want to explain it all to you Gaz… Please just…” He groaned and hugged his legs to his chest. “Just leave Zim alone.” He didn’t look over at her as she sighed and left, heading back home.

She made it back home in time for lunch and tried to push her thoughts to the side to enjoy going out with her family. It was a nice time, and their Dad even got Dib to smile. Once lunch was over he had to get back to work and Gaz waited until they were home before punching Dib.

“Seriously Gaz?!”

“You are such a fucking moron.”

“Gee thanks.”

“Maybe you should go talk to your boyfriend instead of rolling your eyes at me.” She growled out. Dib frowned and crossed his arms.

“Why? What did he tell you? Since he apparently wouldn’t tell me.”

“You were probably freaking out like always! And… he didn’t tell me much. Just that Irkens can’t keep a baby, or whatever he calls it, if their partner doesn’t want it.” She groaned, resisted the urge to punch Dib again, and flopped onto the couch. “He doesn’t actually have a choice without you.” She barely managed to finish the sentence before the door slammed shut as Dib sprinted out.

Dib burst through Zim’s door, catching Gir out of habit as the robot giggled.

“HI MARY!”

“Where’s Zim?”

“Mastah’s still downstairs! He wanted left alone! I made tacos! You want one?”

“Not right now.” He set Gir down and hurried downstairs. Once there he headed to the bedroom when he didn’t see Zim in the lab. Quietly knocking on the door he waited nervously. Zim opened it with a frown.

“What do you want Dib?”

“Do you want the baby Zim?” Dib’s hand shook as he reached out to Zim.

“You don’t.” He pulled away from Dib’s touch and sat back on the bed with a scowl.

“That’s not what I asked Zim.”

“Ugh! Why does it matter Dib?! You don’t! So there will be no smeet! Why does this bother you?!”

“Because it shouldn’t just be up to me! Can you…” Dib groaned and sat on the floor. “Can you at least explain to me _why_ you don’t get a choice?” When Zim didn’t answer Dib looked over sadly. “ _Please_ Zim. I want to understand. I _need_ to.”

“… I guess you should…” He got up and went to sit next to Dib on the floor. Dib pulled him onto his lap and wrapped his arms around him. Zim leaned into the touch with a sigh. “When Irkens get pregnant there is a time period about two months later where we would need to… make sure it sticks. If it’s not done we miscarry. It… worked as a population control before we switched to mainly cloning smeets. It also made sure that the pair wanted a smeet and were in a place where they could have one…” Zim buried his face into Dib’s shirt.

“Ok… That explains a lot I guess… How do you make it stick?”

“Copulation.” Zim mumbled. Dib blushed to his ears and bit his lip before looking back down at the morose alien.

“Right…” His brow furrowed. “I don’t want to choose for you Zim…” He kissed an antenna. “If you want the smeet we can have it. But only if you want it.” Zim’s head snapped up to stare at Dib with shining eyes.

“I… I _really_ do Dib.” He whispered as a tear ran down his cheek. “I want the smeet so much.”

“Then we’ll have it.” He smiled and kissed a tear away. “Maybe tonight we can…” He frowned when Zim’s eyes widened suddenly and he pulled away.

“Oh no… Computer! How much time is left?!”

**“38 minutes remaining.”**

“Wait, what?” Dib looked down at Zim and grabbed his hands when they started tugging at Dib’s pants. “Woah Zim, hold on.”

“There’s no time!”

“What do you mean?!”

“Will you let me go?! We need to have the sex now! There’s only 38 minutes before the miscarriage!”

 **“36 minutes now.”** The computer chimed in helpfully as Zim panicked. Dib let go of Zim and let his pants get pulled off. He blushed and ran a hand through his hair when Zim grabbed his flaccid dick.

“No! Why is it soft Dib?! Make it hard!”

“Damnit Zim… I can’t just get hard in an instant. I mean we had just decided to keep the kid which isn’t helpful to this problem. And now there’s a time constraint?!” Zim paused for a moment to look up at Dib, antennae lowered.

“Do you not want to have sex with Zim?”

“Of course I do Zim! Just… a little foreplay is needed right now, ok?”

“… Evidently Zim should not have left your room two nights ago. You didn’t have this problem _then_.” Zim peered at Dib before smirking as the human’s blush darkened. Zim shuffled back and leaned down before flicking his tongue out and wrapping it around Dib’s dick, coaxing it up. Dib groaned at both the sight and feeling before yelping as Zim suddenly sucked it entirely into his mouth and sucked hard. Dib felt himself quickly rising to action and panted.

“Fuck Zim…” He whined as Zim got up, pulling Dib up as well. He turned to the bed, but Dib pulled him back for a kiss, quickly pushing his tongue in and enjoying as Zim’s tongue wrapped around it. He gently stroked one of Zim’s antenna and glided a hand up the alien’s shirt before dipping down to tug at his waistband. Zim pulled away long enough to pull his shirt off before aggressively kissing Dib again, his tongue beginning to snake down Dib’s throat. Dib backed them up until Zim hit the edge of the bed and fell onto it with a yelp. Dib grinned and pulled Zim’s leggings off before kneeling down.

“Diiib…” Zim whined. “That’s not where you need to be for this. We need to hurry…” Dib paused to raise a brow at Zim.

“Your dick isn’t even out yet Zim, and you’re barely wet. I’m not going to fuck you if you aren’t ready.”

“But- _Oh_!” Zim groaned out as Dib licked his slit, tongue just barely pressing into the opening for the tentacle. He smirked when it began to emerge and went down to thrust his tongue inside Zim, earning a strangled yell from above him. Soon Zim’s hands were tugging in his hair and he lifted his head, licking the iridescent fluid from his lips.

“Feel good Zim?” He leaned up and kissed his neck as Zim moaned quietly.

“Ah… Dib… Please… Stop teasing me.” He turned his head to give Dib more room and Dib bit down as a reward as he lined himself up, feeling Zim’s tentacle eagerly wrapping around to help. With a low groan he slowly pushed in. He stayed still for a moment until Zim began rolling his hips around. Answering his unspoken request Dib pulled out until only the head was inside before slamming back inside, earning a shriek and Zim’s claws scrabbling along Dib’s shirt, causing small tears.

“There’s a good alien. You feel great Zim.” He moaned and reached up to fondle Zim’s antennae as he picked up the pace. Zim began to chirp between moans beneath him and Dib felt heat pooling in his gut. “Zim… I’m so close.” He groaned and kissed Zim, letting the serpentine tongue push into his throat. A minute later Zim pulled away with a scream as he came, clamping down around Dib and his tentacle spasming as it coated Dib’s shirt and Zim’s stomach. Dib managed a few more thrusts before finally spilling inside Zim. He trembled as he came, excess oozing out of the tight space. They both panted as Dib pulled out and rolled to lay next to Zim who immediately turned to cuddle into his side.

“Computer… How much time was left?” He murmured, not willing to even look up.

 **“Time left was 2 minutes.”** Zim sighed in relief, looking up when Dib began to laugh.

“What’s funny?”

“Nothing… Just… I dunno Zim. The fact that we made the time limit is pretty amazing.” He grinned and kissed the top of Zim’s head. “I’m happy.”

“Good. Zim is happy too.” He smiled lazily up at Dib.

“I can’t wait to see how big around you’ll get now.” He laughed as Zim smacked him.

“DIB!”

**Notes for the Chapter:**

> Looks like we got the good end!
> 
> Let me know if you'd like to see the sad ending as well. I could still write it and post separately in the series.

**Author's Note:**

> Comments are very much appreciated.


End file.
